<PRE><B>Question 1063307</B>
mean is 121.238
sd=11.080
df=41 (there were 42 observations)
t(0.95,41)=1.6829; the next is t(0.975,41) and then t(0.995,41)
90% CI=121.24+/-1.6829(11.08/sqrt(41)); Std error, the last part, is 2.95, (118.29,124.19)
95% CI=121.24+/-2.0196(11.08/sqrt(41)); SE is 3.49, (117.75, 124.73)
99% CI=121.24+/-2.7012(11.08/sqrt (41)); SE is 4.67 (116.57, 125.91)

Assumptions: data are readings of something taken using an appropriate  random sample from a population that is normally distributed and the standard deviation of the sample may be used to approximate the standard deviation of the population.

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